Validation of a postoperative prognostic model consisting of tumor microvascular invasion, size, and grade to predict disease-free and cancer-specific survival of patients with surgically resected renal cell carcinoma.

Objectives: To determine the value of microvascular invasion, tumor size, and Fuhrman grade to predict the survival of patients with surgically resected renal cell carcinoma (RCC).

Methods: A total of 771 consecutive patients (T1-4, Nx, M0) were retrospectively reviewed. For each patient with RCC, the prognostic Sao Paulo score (SPS) was calculated using the following variables: tumor size (>7 cm vs
Results: Median follow-up was 80 months. DFS rates after 5 years were 91.2%, 61.3%, and 51.9% in the original SPS LR, IR, and HR groups, respectively. CSS rates after 5 years were 94.3%, 79.8%, and 58.7%, respectively (P < 0.001). Each original SPS constituent revealed a significant influence on DFS and CSS in the multivariate analysis. By modification of the cut-off value of the maximum tumor size from 7 to 5 cm the predictive value of the SPS sum score was marginally enhanced. Using a cut-off value of 5 cm also resulted in a relatively better discrimination between the IR and the HR group regarding DFS and CSS.

Conclusions: Stratifying RCC patients by SPS into LR, IR, and HR groups provides a clinically useful tool for outcome analysis and risk assessment. However, the prognostic value of the SPS could be enhanced by including a maximum tumor size with a cut-off at 5 cm into the sum score.